A dosing unit for dosing fluids from the inlet of a primary dosing section (10) to the outlet of a secondary dosing section comprises a membrane (12) with at least one opening (16) which acts as a flow resistance to a medium to be dosed. A pressure sensor (14) is integrated into the membrane, to determine the pressure difference between the inlet and the outlet. The dosing unit has a pressure transmitter at the inlet, and the primary and secondary dosing sections are arranged one behind the other, to allow flow resistance to be detected due to pressure drop. USE - The arrangement is used as a dosing unit, e.g. in medicine. ADVANTAGE - The arrangement has a simple construction and allows precise dosing.